Combined Network Switching and Filter System and Method

ABSTRACT

A switchable filter and diplexer circuit includes a plurality of bandpass filters having passbands for the frequency bands in which communication across a communication channel is desired and a plurality of diplexers, the diplexers having a plurality of passbands. A plurality of switches are provided to select one of the bandpass filters or diplexers from among the plurality of bandpass filters and diplexers for communication on a communication channel. An additional switching capability is provided to select a first passband of a given diplexer when a second passband of that diplexer is selected by the plurality of switches.

TECHNICAL FIELD

The present invention relates generally to network communications, andmore particularly, some embodiments relate to combined multi-banddiplexers and bandpass filters for network and television signalcommunication.

DESCRIPTION OF THE RELATED ART

A local network may include several types of devices configured todeliver subscriber services throughout a home, office or other likeenvironment. These subscriber services include delivering multimediacontent, such as streaming audio and video, to devices locatedthroughout the location. As the number of available subscriber serviceshas increased and they become more popular, the number of devices beingconnected the home network has also increased. The increase in thenumber of services and devices increases the complexity of coordinatingcommunication between the network nodes. This increase also generallytends to increase the amount and types of traffic carried on thenetwork.

The network of FIG. 1 is one example of a multimedia network implementedin a home. In this example, a wired communications medium 100 is shown.The wired communications medium might be a coaxial cable system, a powerline system, a fiber optic cable system, an Ethernet cable system, orother similar communications medium. Alternatively, the communicationsmedium might be a wireless transmission system. As one example of awired communication medium, with a Multimedia over Coax Alliance (MoCA®)network, the communications medium 100 is coaxial cabling deployedwithin a residence 101 or other environment. The systems and methodsdescribed herein are often discussed in terms of this example homenetwork application, however, after reading this description, one ofordinary skill in the art will understand how these systems and methodscan be implemented in alternative network applications as well as inenvironments other than the home.

The network of FIG. 1 comprises a plurality of network nodes 102, 103,104, 105, 106 in communication according to a communications protocol.For example, the communications protocol might conform to a networkingstandard, such as the well-known MoCA standard. Nodes in such a networkcan be associated with a variety of devices. For example, in a systemdeployed in a residence 101, a node may be a network communicationsmodule associated with one of the computers 109 or 110. Such nodes allowthe computers 109, 110 to communicate on the communications medium 100.Alternatively, a node may be a module associated with a television 111to allow the television to receive and display media streamed from oneor more other network nodes. A node might also be associated with aspeaker or other media playing devices that plays music. A node mightalso be associated with a module configured to interface with aninternet or cable service provider 112, for example to provide Internetaccess, digital video recording capabilities, media streaming functions,or network management services to the residence 101. Also, televisions107, set-top boxes 108 and other devices may be configured to includesufficient functionality integrated therein to communicate directly withthe network.

With the many continued advancements in communications technology, moreand more devices are being introduced in both the consumer andcommercial sectors with advanced communications capabilities. Theintroduction of more devices onto a communication network can task theavailable bandwidth of communication channels in the network. Forexamples, service providers such as satellite TV providers include MoCAenabled set-top boxes (STBs) and digital video recorders (DVRs) withtheir systems. By using a high-speed MoCA network to connect DVRs, STBsand broadband access points, the satellite TV providers offer multi-roomDVR from a single box and allow access to the Internet to providestreaming video on demand.

To accommodate additional devices the network bandwidth can be dividedinto different frequency bands to allow some level of simultaneouscommunication with reduced interference. For example, to operate onexisting coaxial runs in the home, MoCA is capable of operating atdifferent frequency bands to avoid existing cable TV signals. Forexample, in a home with cable TV signals below 1 GHz, MoCA operatesabove 1125 MHz in a band called D band. In a home with satellite L-bandsignals above 950 MHz MoCA operates between 475 and 675 MHz in a bandcalled E band. To further reduce interference to existing services, MoCAalso features transmit power control (TPC). TPC reduces the MoCAtransmit power by up to 30 dB. Reducing transmit power lowers thelikelihood that the MoCA signal will cause interference to devicesoperating in other bands. To further take advantage of the bandwidthprovided by the coaxial cabling, channel stacking switch (CSS)technology is often used to re-allocate IF video to another portion ofthe coaxial cable to provide separate channels for a MoCA home network.

To accommodate multiple devices on a given communication channel, adiplexer can be used. For example, a conventional diplexer includes twoor more bandpass filters to allow multiple signals in differentfrequency bands to share the same communication link and to filter outthe unwanted signals before providing the signal to a given device. Suchdiplexers can provide a frequency division duplexing (FDD) solution.

Additionally, switchable diplexers can be used to allow selective accessto the physical layer by different signals in different frequency bands.This is useful in applications where it is desirable to allow multipledevices operating at different frequency bands to share the same coaxialcable network. FIG. 2 is a diagram illustrating an example of aconventional switchable diplexer. Referring now to FIG. 2, thisconventional diplexer 200 includes four bandpass filters and sixswitches to select one of the four bandpass filters for communication.Particularly, this example includes a D-Band bandpass filter 204, anF-Band bandpass filter 206, a D-Low-Band bandpass filter 208, and anE-Band bandpass filter 210. D-Band bandpass filter 204 is configured topass signals in the 1,125 MHz to 1,675 MHz passband range, and to rejectsignals outside that passband range. Likewise, the F-Band bandpassfilter 206 has a passband of 650 MHz-875 MHz with high rejectionrequirements in the 1300-2150 MHz range, the D-Low-Band bandpass filter208 has a passband of 1,125 MHz to 1,225 MHz, and the E-Band bandpassfilter 210 has a passband of 475 MHz to 675 MHz and high rejectionspecification from 950 MHz to 2,150 MHz.

Switches, SW1-SW6 are provided to switch the selected bandpass filterinto the signal path. In the illustrated example, three switches SW1,SW2 and SW5 are provided at a first side to switch the signal to/fromthe desired one of the plurality of bandpass filters 204-210. Whenconfigured as shown, switches SW1, SW2 and SW5 are configured to switchthe signal to/from E-Band bandpass filter 210. Likewise, at the otherside, three switches SW3, SW4 and SW6 are provided to switch the signalto/from the selected bandpass filter onto the signal path. Whenconfigured as shown, switches SW3, SW4 and SW6 are configured to switchthe output signal to/from E-Band bandpass filter 210 from/onto thecommunication channel. As used in this document, top-level switches suchas switches SW1 and SW4 are referred to as primary switches, while thenext level switches SW2, SW3, SW5 and SW 6 are referred to as secondaryswitches.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

According to embodiments of the systems and methods described herein,various configurations for switchable bandpass filter and diplexercombinations are provided. In accordance with some embodiments of thesystems and methods described herein, a plurality of diplexers andbandpass filters are provided with switches to allow selection ofdifferent communication bands for communication over a communicationchannel. Particularly, in some embodiments, switchable bandpass filterand diplexer combinations are provided to allow communication of networkand cable TV signals over a coaxial cable installation. Moreparticularly, in some embodiments, switchable bandpass filter anddiplexer combinations are provided to allow communication of MoCAnetwork communications and cable TV signals over a coaxial cableinstallation.

In some embodiments, a switchable filter and diplexer circuit, includesa plurality of diplexers, each diplexer having a plurality of one ormore passbands. For example, in some embodiments, a given diplexerincludes a passband for network communications (such as, for example,MoCA network communications) and a passband for cable TV transmission.The switchable filter and diplexer circuit in these embodiments alsoincludes a plurality of bandpass filters having a predetermined passbandand stopband. Preferably, at least some of the bandpass filters have apassband different from the passband of the other of the plurality ofbandpass filters.

A plurality of switches may be provided and coupled to the diplexers andto the passband filters. The switches may be configured to select one ofthe plurality of bandpass filters or diplexers for signal communicationon a communication channel.

In some embodiments, the bandpass filters are arranged in groups ofbandpass filters located adjacent to one another physically, and a groupof bandpass filters includes a plurality of bandpass filters having astop band in a common frequency range of interest.

A variety of different switching arrangements can be provided to allowselection and communication of network and television signals. In oneembodiment, the plurality of switches comprise a first pair of switchescoupled to the plurality of bandpass filters and diplexers andconfigured to select one of the bandpass filters and diplexers fornetwork communication, and a third switch having input terminals coupledto the diplexers and configured to select one of the diplexers for TVsignal communication. In some embodiments, the third switch is coupledto at least one of the switches of the first pair of switches such thatwhen a given diplexer is selected by the at least one of the switches ofthe first pair of switches that same diplexer is selected by the thirdswitch.

In various embodiments, the diplexers include a cable TV bandpassfilter. The cable TV bandpass filter can include a low-pass filterconfigured to have a passband of less than or equal to 1002 MHz. Inother embodiments, the cable TV bandpass filter can include a low-passfilter configured to have a passband for other TV signals such as, forexample, a passband of less than or equal to 864 MHz.

In some embodiments, a switchable filter and diplexer circuit includes afirst switch having a common terminal and a plurality of selectableterminals; a second switch having a common terminal and a plurality ofselectable terminals; a third switch having a common terminal and aplurality of selectable terminals; a plurality of diplexers, eachdiplexer having a plurality of passbands and each diplexer having afirst terminal connected to one of the plurality of selectable terminalsof the first switch, a second terminal connected to one of the pluralityof selectable terminals of the third switch, and a third terminalconnected to one of the plurality of selectable terminals of the secondswitch; and a plurality of bandpass filters, the bandpass filters havinga predetermined passband, wherein at least some of the bandpass filtershave a passband different from the passband of the other of theplurality of bandpass filters, each of the bandpass filters having afirst terminal connected to one of the plurality of selectable terminalsof the first switch, a second terminal connected to one of the pluralityof selectable terminals of the third switch.

In some embodiments, the bandpass filters include an E-band bandpassfilter, an F-band bandpass filter and an H-band bandpass filterelectrically arranged in parallel relation to one another and thediplexers comprises a first diplexer with a D-band bandpass filter, asecond diplexer with a D-low band bandpass filter, and a third diplexerwith a D-high band bandpass filter electrically arranged in parallelrelation to one another. The diplexers can further include a cable TVbandpass filter having, for example, a low-pass filter configured tohave a passband of less than or equal to 1002 MHz.

The bandpass filters may be arranged in groups of bandpass filterslocated adjacent to one another physically, wherein a group of bandpassfilters comprises a plurality of bandpass filters having a stop band ina common frequency range of interest. The bandpass filters can include aplurality of bandpass filters each having an identified rejectionfrequency range that is at least partially overlapping an identifiedfrequency rejection range of the other bandpass filters in the group.The identified rejection frequency range can be a predeterminedfrequency range of high rejection.

The bandpass filters and diplexers may be grouped into M groups of Nbandpass filters or diplexers each, wherein the first and third switchesinclude a first and third switch pair for each group of bandpass filtersor diplexers. The system can further include a first primary switchhaving a common terminal and at least M selectable terminals, and asecond primary switch having a common terminal at least M selectableterminals, wherein corresponding ones of the selectable terminals of thefirst and second primary switches are connected to the common terminalsof the first and third switches for a given group of bandpass filters ordiplexers. In some embodiments, N is the same quantity of bandpassfilters or diplexers for each of the M groups. In other embodiments, Nis a different quantity of bandpass filters or diplexers for one or moreof the M groups.

Because it is often desirable to share the channel among componentsoperating at different frequencies, at least some of the bandpassfilters have a passband different from the passband of the other of theplurality of bandpass filters. A plurality of switches can be providedto switch the desired bandpass filter into the circuit to allowcommunication on its corresponding band. The switches can therefore beelectrically coupled to the passband filters and configured to selectone of the plurality of bandpass filters for signal communication on thecommunication channel. In various embodiments, the bandpass filters arearranged in groups of bandpass filters located adjacent to one anotherphysically. Further, a group of bandpass filters comprises a pluralityof bandpass filters having a stop band in a common frequency range ofinterest.

In some configurations multi throw switches can be used to switch abandpass filter with a desired into and out of the circuit with onelevel of switches. In other configurations, the switches are provided asprimary-level switches and secondary switches. The primary switches canbe used to select groups of bandpass filters into and out of thecircuit; the secondary switches can be used to select a given bandpassfilter within the group. Accordingly, in some embodiments, the pluralityof bandpass filters in a given group of bandpass filters share commonsecondary switches. In further embodiments, additional levels ofswitching can be provided such as, for example, to accommodate subgroupsof bandpass filters. To provide additional isolation, some embodimentscan be provided in which none of the plurality of bandpass filters in agiven group share a common secondary switch with a bandpass filter inanother group.

In one example embodiment, the groups of bandpass filters include atleast two groups of at least two bandpass filters each, and the switchesinclude primary switches and secondary switches. In a further example,the switchable diplexer includes two primary switches each connected toa communication link and configured to switch one of the two groups intothe communication link; and a pair of secondary switches for each groupof bandpass filters, each pair of secondary switches having a firstsecondary switch coupled to one of the primary switches and a secondsecondary switch coupled to the other of the primary switches, each pairof secondary switches configured to select one of the two bandpassfilters in their respective group.

The switchable diplexer in various embodiments is scalable depending onsystem requirements and the groups of bandpass filters can include Mgroups of N bandpass filters each (where M, N are integer numbers). Thenumber of bandpass filters N in each of the M groups can be the sameacross all groups or it can vary for one or more of the groups. In otherwords, in some embodiments N is the same quantity for each of the Mgroups of bandpass filters, while in other embodiments, N is differentfor one or more of the M groups. In embodiments with primary andsecondary switches, there can be two primary switches each connected toa communication link and configured to switch one of the M groups intothe communication link. There can also be included a pair of secondaryswitches for each of the M group of bandpass filters, each pair ofsecondary switches having a first secondary switch coupled to one of theprimary switches and a second secondary switch coupled to the other ofthe primary switches, each pair of secondary switches configured toselect one of the N bandpass filters in their respective group.

In embodiments with primary and secondary switches are used, in someembodiments when the primary switches are configured to select one ofthe groups of bandpass filters, the other of the M groups of bandpassfilters are deselected by the primary switches, and further wherein eachpair of secondary switches for the deselected groups of bandpass filtersare set in a complementary configuration.

In various embodiments, bandpass filters can be cascaded with a diplexerto create a cascaded diplexer leg with selectable passbands. This can,in some embodiments, simplify the design and alleviate the need forswitching to select TV bands at the diplexer output while still allowingmulti-band network support.

In one embodiment, a cascaded diplexer circuit, includes a diplexercomprising a plurality of first bandpass filters each having a passband;and a second bandpass filter having a passband and two terminals, andcoupled in series with a determined one of the first bandpass filters ofthe diplexer; and first and second switches coupled in series with thesecond bandpass filter and the determined one of the first bandpassfilters of the diplexer, and configured to selectably switch the secondbandpass filter into the circuit. Preferably, the passband of the secondbandpass filter is chosen to limit the passband of the determined one ofthe first bandpass filters, such that when the second bandpass filter isswitched into the circuit, the passband of the diplexer leg is reduced.In some embodiments, the passband of the second bandpass filter is asubset of, or overlaps with, the passband of the determined one of thefirst bandpass filters.

The cascaded diplexer circuit can be further configured to include aplurality of additional bandpass filters connected in parallel with thediplexer and second bandpass filter, the additional bandpass filtershaving a predetermined passband; and second and third switches coupledto the additional passband filters and to the diplexer and secondbandpass filter circuit leg, the second and third switches configured toselect one of the plurality of additional bandpass filters or thediplexer and second bandpass filter circuit leg for signal communicationon a communication channel.

A shunt can be included and coupled between the first and secondswitches and arranged in parallel circuit relation to the secondbandpass filter to allow the second bandpass filter to be effectivelyremoved from the circuit. Also, a third bandpass filter can be includedand coupled between the first and second switches and in parallelcircuit relation to the second bandpass filter. Additional bandpassfilters can also be provided. The first and second switches can beconfigured to selectably connect the second bandpass filter, the thirdbandpass filter or the shunt into the circuit. In some embodiments, thefirst and second switches are configured to selectably connect thesecond bandpass filter or the third bypass filter into the circuit.

In other embodiments, a cascaded diplexer circuit includes: diplexercomprising a common terminal and first and second band-specificterminals, and further comprising a first bandpass filter coupledbetween the common terminal and the first band-specific terminal and asecond bandpass filter coupled between the common terminal and thesecond band-specific terminal, the bandpass filters having a passbandand a stop band; a third bandpass filter having first and secondterminals, wherein the first terminal of the third bandpass filter iscoupled to the first band-specific terminal of the diplexer; and a firstswitch having a common terminal coupled to the first band-specificterminal of the diplexer and a first selectable terminal coupled to afirst terminal of the third bandpass filter, wherein the switch isconfigured to selectably switch the third bandpass filter into and outof the diplexer circuit. Preferably, in some embodiments, the passbandof the third bandpass filter limits the passband of the first bandpassfilter. Accordingly, the passband of the third bandpass filter can be asubset of, or overlap with, the passband of the first bandpass filter.

The cascaded diplexer circuit can further include a plurality ofadditional bandpass filters connected in parallel with the diplexer andthird bandpass filter, the additional bandpass filters having apredetermined passband; and second and third switches coupled to theadditional passband filters and to the diplexer and third bandpassfilter circuit leg, the second and third switches configured to selectone of the plurality of additional bandpass filters or the diplexer andthird bandpass filter circuit leg for signal communication on acommunication channel.

The cascaded diplexer circuit can also include a second switch having afirst selectable terminal coupled to a second terminal of the thirdbandpass filter, and a shunt arranged in parallel circuit relation tothe third bandpass filter and coupling between a second selectableterminal of the first switch and a second selectable terminal of thesecond switch. A fourth bandpass filter coupled between the first andsecond switches can also be included and arranged in parallel circuitrelation to the third bandpass filter. In some embodiments, the firstand second switches are configured to selectably connect the thirdbandpass filter, the fourth bandpass filter or the shunt into thecircuit.

The cascaded diplexer circuit can also include a fourth (or more)bandpass filter coupled between the first and second switches and inparallel circuit relation to the third bandpass filter. In suchembodiments, the first and second switches can be configured toselectably connect the fourth bandpass filter or the third bypass filterinto the circuit. The additional bandpass filters can include at leastone of an E-band bandpass filter, an F-band bandpass filter and anH-band bandpass filter electrically arranged in parallel relation to oneanother.

Other features and aspects of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, the featuresin accordance with embodiments of the invention. The summary is notintended to limit the scope of the invention, which is defined solely bythe claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, in accordance with one or more variousembodiments, is described in detail with reference to the accompanyingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the invention. Thesedrawings are provided to facilitate the reader's understanding of thesystems and methods described herein and shall not be consideredlimiting of the breadth, scope, or applicability of the claimedinvention.

FIG. 1 is a diagram illustrating one example of a home networkenvironment with which the systems and methods described herein can beimplemented.

FIG. 2 is a diagram illustrating one example of a conventionalswitchable diplexer.

FIG. 3 is a diagram illustrating an example of a switchable diplexer inaccordance with one embodiment of the systems and methods describedherein.

FIG. 4 is a diagram illustrating an example of a switchable diplexer inaccordance with another embodiment of the systems and methods describedherein.

FIG. 5 is a diagram illustrating an example of a combination switchablediplexer in accordance with one embodiment of the systems and methodsdescribed herein.

FIG. 6 is a diagram illustrating another example of a combinationswitchable diplexer in accordance with one embodiment of the systems andmethods described herein.

FIG. 7 is a diagram illustrating an example of a cascaded switchablediplexer in accordance with one embodiment of the systems and methodsdescribed herein.

FIG. 8 is a diagram illustrating another example of a cascadedswitchable diplexer in accordance with one embodiment of the systems andmethods described herein.

The figures are not intended to be exhaustive or to limit the inventionto the precise form disclosed. It should be understood that theinvention can be practiced with modification and alteration, and thatthe invention be limited only by the claims and the equivalents thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

Systems and methods described herein include a switchable diplexerconfigured in some embodiments to provide a low insertion loss relativeto conventional solutions. Because of crosstalk between diplexerelements used in switchable diplexers, the switching components ofswitchable diplexers are often specified to have a high enough degree ofisolation to reduce or minimize the adverse effects of signals bleedingthrough onto an adjacent diplexer channel. Configuration of theswitchable diplexer to provide placement of components such thatbandpass filters having like passbands are placed adjacent one anotherhelps to reduce the effects of unwanted crosstalk interference betweenthe bandpass filter elements.

The diplexers according to the systems and methods describe hereininclude a plurality of bandpass filters that are used to allow signalsof certain frequencies to pass while rejecting, or filtering out,signals in other frequency bands. The bandpass filters pass signalswithin a certain band of frequencies of a desired bandwidth. This isknown as the pass band of the bandpass filter. The bandwidth istypically defined as the frequency range between two cut-off points. Thefrequency cutoff points are typically 3 dB below the maximum center orresonant peak, although other parameters can be used to specify theoperable passband of the bandpass filter. Frequency ranges outside thepassband are often referred to as the stop band of the bandpass filter.With some filters there may be a transition region between the passbandand the stop band. In most applications, the bandpass filter is used toallow frequencies within the passband to be passed through the filterwhile rejecting, or filtering out, unwanted frequencies outside thepassband.

In addition to specifying a passband, bandpass filters may specify alevel of rejection (typically in dB) for the stop band. Also, one ormore frequency ranges of high rejection may be specified to filter outsignals in a frequency range of particular interest. The level ofrejection specified as being a high level of rejection for the filterdepends on the system application and the signals anticipated on thecommunication channel. For example, it may be known in a givenapplication that signals in a certain frequency range may be present andthat such signals, if allowed to pass, would cause interference on thechannel with desired signals in the passband. As such, the systemdesigner would specify a sufficient level of rejection in that band (oracross a wider band) to reduce the interference to a desired level toallow system performance to meet specifications. For example, in someapplications such as in MoCA, the specification for high rejection inthe 1300-2150 MHz range for F-Band bandpass filter 206 can be 65 dB,while the specification for high rejection in the 950-2150 MHz range forE-band bandpass filter 210 can be 60 dB. As one of ordinary skill in theart will understand, other levels of isolation can be specified for afrequency range of high rejection. Note that in some applications, theentire stop band may be specified as requiring a high level ofrejection.

Conventional designs such as that shown in FIG. 2 alternate theplacement of bandpass filters so that filters having different passbandsare placed adjacent to one another physically. This is done withconventional switchable diplexers to reduce coupling or crosstalk forbetter isolation. Accordingly, in the example of FIG. 2, the physicallayout of bandpass filters 204-210 would be similar to the layout shownin the schematic diagram, in which D-Band bandpass filter 204 and D-Lowband bandpass filter 208 are physically separated from each other toavoid cross talk between signals within the overlapping frequency rangeof their respective passbands.

However, as a result, bandpass filters with different andnon-overlapping passbands are typically placed adjacent one another. Dueto crosstalk between adjacent bandpass filters, signals filtered out orrejected by the selected bandpass filter may be coupled into an adjacentbandpass filter and pass through the output switch and onto the signalpath. This phenomenon can be illustrated with the example configurationshown in FIG. 2. With continued reference to FIG. 2, consider the caseas illustrated in which a broadband signal is input into switchablediplexer 200 at switch SW1, is routed to switch SW5, which in turn,routes the signal to E-Band bandpass filter 210. E-Band bandpass filter210 passes the portion of the signal from 475 MHz to 675 MHz to switchSW6. E-Band bandpass filter 210 blocks portions of the signal outsideits passband frequency band in accordance with the filtercharacteristics. For example, in one application, E-Band bandpass filter210 blocks signals in the 950 MHz-2150 MHz by 60 dB or greater.

However, because of the proximity of D-Low Band bandpass filter 208 toE-Band bandpass filter 210 and the crosstalk between them, unwantedsignals can couple into D-Low Band bandpass filter 208. Particularly,portions of the signal in the stop band of E-Band bandpass filter 210that are in the passband of D-Low Band bandpass filter 208 can coupleonto and be passed by D-Low Band bandpass filter 208. This can beparticularly problematic in the instant example where frequency rangespecified as the high-rejection range of E-band bandpass filter 210overlaps to a large extent with the pass band of D-low band bandpassfilter 208. Accordingly, signals in this area of specified highrejection can couple into and be passed by D-low band bandpass filter208, degrading the effective rejection in that band.

To avoid having this crosstalk signal appear at the output of theswitchable diplexer 200, system designers typically specify outputswitches with a high enough level of isolation to avoid this unwantedsignal from coupling across the terminals of the switch and onto theoutput signal lines. Continuing with this particular example, E-bandbandpass filter 210 requires high rejection in the 950 MHz-2150 MHzrange (for example, 60 dB), which overlaps with the passband of theD-Low Band bandpass filter 208 (1,125 MHz-1,225 MHz). Therefore, thecombined isolation ISO5+ISO6 of switches SW5 and SW6 needs to be largeenough to sufficiently isolate D-low band bandpass filter 208. Consideran example where the high rejection is specified as being 60 dB. In thisexample, because of coupling from E-band bandpass filter 210 to D-lowband bandpass filter 208, the combined switch isolation for switches SW5and SW6 needs to be on the order of approximately 70 dB (60 dB+10 dBmargin) in order to preserve the integrity of E-Band bandpass filter210.

Accordingly, SW5 and SW6 would be typically specified with sufficientisolation ISO6 between terminals A and B such that unwanted signals willnot couple between terminal B and terminal A. Likewise, the otherswitches SW1-SW5 are also specified with sufficient isolation to avoidsimilar coupling of unwanted signals. For example, F-band bandpassfilter 204 requires high rejection (for example, 65 dB) in the 1,300MHz-2,150 MHz range, which covers the passband of the D-band bandpassfilter (1,125 MHz-1,225 MHz). Therefore the combined isolations of SW2and SW3 (ISO2 and ISO3) needs to be in the 75 dB range (65+10) in orderto preserve the integrity of F-band bandpass filter 204. Switches withthese levels of isolation are costly and can drive up the cost of theswitchable diplexer 200.

One solution to reduce or eliminate unwanted filter crosstalk would beto provide a large enough degree of physical separation between thebandpass filters to reduce or eliminate the crosstalk between them.However, packaging constraints typically require that the bandpassfilters be placed in close enough proximity to one another such thatcrosstalk needs to be addressed. Therefore, according to one embodimentof the systems and methods described herein, the bandpass filters arearranged counter-intuitive to conventional wisdom. Particularly, in someembodiments, the bandpass filters are arranged such that filters withlike passbands are placed adjacent to one another, and filters withdiffering passbands are preferably separated from one another. In otherembodiments, the bandpass filters are arranged such that a filter with aspecified high rejection in a given frequency range is placed adjacent abandpass filter for which that same frequency range is in its stop band.In yet other embodiments, the bandpass filters are arranged such thatbandpass filters with like stop bands are placed adjacent to oneanother.

In some embodiments, the placement is made to the extent practicalconsidering packaging, layout, and other constraints that may exist forthe switchable diplexer. For example, in some applications, packaging,layout or other constraints may require that one or more bandpassfilters be placed adjacent to one or more other bandpass filters havingdiffering passbands.

In some embodiments, two bandpass filters are considered to havediffering passbands where the passbands of the two bandpass filters arecompletely non-overlapping. In other embodiments, two bandpass filtersare considered to have differing passbands where the passbands of thetwo bandpass filters are only partially non-overlapping. In someembodiments, two bandpass filters are considered to have like passbandswhere the passband of one filter is the same or substantially the sameas the passband of the other filter. In other embodiments, two bandpassfilters are considered to have like passbands where the passband of onefilter overlaps some or all of the passband of the other filter, orwhere the passband of one filter is a subset of the passband of theother filter. Accordingly, overlap of frequency bands can include thepartial or complete overlap by one band of one filter with a frequencyband of another filter.

In some embodiments, the amount of overlap for a band of one filter tobe considered like a band of another filter is determined by apercentage of overlap by one band of the other. For example, 50%, 60%,70%, 80%, 90% or greater overlap may be considered sufficient overlap offrequency bands for two filters to be deemed to have like passbands orstop bands.

In many embodiments, the passbands and stop bands of the filters, aswell as bands of high rejection, are defined by the network parameters.Accordingly, a certain percentage of overlap may not be attainable foreach adjacent filter, but adjacencies instead determined based onoptimizing the layout given the passband and stopband ranges provided.Filter layout and adjacencies can be determined by choosing thearrangement that minimizes stop-band crosstalk among the filters. Infurther embodiments, Filter layout and adjacencies can be determined bychoosing the arrangement that minimizes stop-band crosstalk for highrejection bands.

FIG. 3 is a diagram illustrating an example bandpass filter layout of aswitchable diplexer in accordance with one embodiment of the systems andmethods described herein. In the example illustrated in FIG. 3, thebandpass filters are arranged such that filters with like stopbands areplaced adjacent to one another, and filters with differing stopbands areseparated from one another. Referring now to FIG. 3, the illustratedswitchable diplexer 300 includes bandpass filters 302-308 and switchesSW11-SW16. Like the example shown in FIG. 2, E, F and D bands areaccommodated and switches SW11-SW16 are provided to switch the selectedbandpass filter into the signal path. In the illustrated example, threeswitches SW11, SW12 and SW15 are provided at one side to switch thesignal into/from the desired one of the plurality of bandpass filters304-310. When configured as shown, primary switch SW11 and secondaryswitches SW12 and SW15 are configured to switch the signal into/fromE-Band bandpass filter 308. Likewise, at the other side, three switches,primary switch SW13 and secondary switches SW14, SW16, are provided toswitch the signal to/from the selected bandpass filter from/to thesignal path. When configured as shown, switches SW13, SW14 and SW16 areconfigured to switch the signal from E-Band bandpass filter 308 to/fromthe communication channel.

As illustrated in the example of FIG. 3, bandpass filters are arrangedin groups such that bandpass filters with like stop bands (or with likepassbands) are positioned adjacent one another rather than in analternating configuration. Therefore, signals outside the passband ofthe selected filter are either completely outside the passband of theadjacent filter or only partially overlapping the passband of theadjacent filter.

With continued reference to FIG. 3, in this example E-band bandpassfilter 308 is positioned adjacent F-Band bandpass filter 304, and D-Bandbandpass filter 302 is positioned adjacent D-low band bandpass filter306. The passband of E-band bandpass filter 308 (475 MHz-675 MHz) isentirely contained with the passband of F-band bandpass filter 304 (650MHz-875 MHz) and therefore, only a portion of those rejected signalsoutside of the passband of E-band bandpass filter 308 are within thepassband of F-band bandpass filter 304. Moreover, none of the signalsrejected by the passband of F-band bandpass filter 304 are within thepassband of E-band bandpass filter 308. More importantly in thisexample, the frequency range for which high rejections are specified forE-band bandpass filter 308 (950 MHz-2150 MHz) is completely outside thepassband (i.e. it falls in the stopband) of F-Band bandpass filter 304.Likewise, the frequency range for which high rejections are specifiedfor F-band bandpass filter 304 (650 MHz-875 MHz) is completely outsidethe passband of E-band bandpass filter 308. Therefore, even if signalsin the stop band of E-band bandpass filter 308 were to couple into thesignal path of F-band bandpass filter 304, those signals would berejected by the stop band of F-band bandpass filter 304.

More particularly, consider an example of a broadband signal input toswitch SW 12. If the portion of that signal in the stop band of E-bandbandpass filter 308 were to couple through switch SW12 to F-bandbandpass filter 304, that signal would be rejected by the stop band ofF-band bandpass filter 304. Likewise, if through crosstalk the signalwere to couple from of E-band bandpass filter 308 to F-band bandpassfilter 304, that signal would be rejected by the stop band of F-bandbandpass filter 304.

As illustrated in the example of FIG. 3, the high rejection area ofE-band bandpass filter 308 is not a part of the passband of F-Bandbandpass filter 304, and vice versa. Therefore the Isolationrequirements (ISO2+ISO3) of the Switches are reduced over theconventional solution illustrated in FIG. 2. In some embodiments, forexample, the isolation requirements ISO2+ISO3 can be reduced to the 30dB range. In other applications, the isolation requirements ISO2+ISO3can be reduced to other levels depending on the bandpass filters used,and system requirements.

Accordingly, switchable diplexer 300 can be implemented to reduce theeffects of parasitic coupling and to improve isolation by the physicalplacement and arrangement of the bandpass filters. For example, wherethe diplexer has a first bandpass filter having a high rejectionrequirement and second bandpass filter that has a passband covering thefirst filter's high rejection band, these bandpass filters are arrangedsuch that they are not physically close to each other. For example, theyare arranged as remotely from one another as layout, packaging andoverall package size constraints allow. In the illustrated example, toaccomplish this the filters are grouped according to similarities ofpassbands or stop bands.

Arranging the bandpass filters in groups to position the bandpassfilters adjacent other bandpass filters with like passbands or like stopbands can improve signal isolation as described further below. In oneembodiment, the bandpass filters can be arranged in M groups, and eachgroup can comprise N bandpass filters. In the example depicted in FIG.3, M=2 and N=2; that is, the bandpass filters are arranged in 2 groupsand each group includes 2 bandpass filters. In some embodiments, thenumber of bandpass filters N in each group is the same across allgroups. In other embodiments, the number of filters N in each group canvary from group to group (i.e., N can be different for one or moregroups). Spacing between bandpass filters in the switchable diplexer canvary or it can be constant. For example, in one embodiment filterspacing can be constant across the entire switchable diplexer. Inanother embodiment, spacing between filters can vary. In yet anotherembodiment, spacing between filters of adjacent groups can be greaterthan or less than spacing of filters within a group. It is noted thatdescription herein of arrangement in terms of groups refers to adjacencyof filters and does not require particular spacing of filters within agroup or between different groups.

In some embodiments, where the packaging or sizing constraints permit,spacing between bandpass filters 306 and 304 can be increased tominimize crosstalk between them. Also, in some embodiments, spacingbetween bandpass filters 302 and 306 and between bandpass filters 304and 308 can be decreased over conventional solutions.

Another benefit of the example illustrated in FIG. 3 is that provided byincreased switch isolation. In the example of FIG. 2, in E-Bandoperation, unwanted signals coupled into D-band bandpass filter 204 areisolated from the output by two switches SW5 and SW6. Likewise, in otherbands of operation, isolation is similarly provided by two switches.

In the example of FIG. 3, the isolation provided by the switches can beincreased. By arranging SW15 and SW16 into opposite, or complementary,positions (as illustrated) when the signal is passing thru SW12 & SW13,(i.e., in E- or F-band operation), isolation is maintained by 3 switches(ISO1+ISO4+ISO5) (or ISO1+ISO6+ISO5) instead of 2 switches in theconventional design. Therefore isolation performance is improved overthe conventional design or lower isolation switches can be used toachieve the same levels of unwanted signal isolation. Table 1 is a tableillustrating an example configuration of switches for switchablediplexer 300 using the complementary positioning of secondary switchesSW12, SW13, SW15 and SW16. Note, in implementations where there are morethan 2 bandpass filters in a given group, the complementary position forthe secondary switches comprises switch positions in which none of thebandpass filters in the group is selected by the switches at both ends.

TABLE 1 SW11 SW14 SW12 SW13 SW15 SW16 A A A A A B A A A A B A A A B B AB A A B B B A B B A A A B B B A A B A B B B B A B B B B B B A

Note, also that even though the passband of D-low band bandpass filter306 over laps with the high rejection region of F-band bandpass filter304 the effects of any crosstalk between them is isolated by theisolation ISO11 provided by switch SW11 on the first end and by switchesSW16 and SW14 at the other end (ISO14 and ISO16). In other words, F-bandbandpass filter 304 and D-band bandpass filter 306 use separatesecondary switches. This can be contrasted to the conventional solutionin which the bandpass filters with the high rejection requirements (206and 210) are paired with a bandpass filter having a passband overlappingthat region (filters 204 and 208, respectively). In the example of FIG.2, each pair shares the same terminal of the primary switches SW1 andSW4, and no isolation between them is provided by these primaryswitches. Also, each pair shares the same secondary switches—i.e.,secondary switches SW12 and SW13 for filter pair 204, 206, and secondaryswitches SW15 and SW16 for filter pair 208, 210. In other words bandpassfilters 204 and 206 are on the same switch branch and no isolation fromcrosstalk between them is provided by primary switches SW11 or SW14. Thesame is true for bandpass filters 208 and 210.

Although the example illustrated in FIG. 3 uses multiple SPDT (singlepole double throw) switches, other embodiments with different switchingarrangements can be used. For example the three input switches SW11,SW12, SW15 can be replaced by a single SP4T switch (not shown) toprovide selectable switching of the signal to one of the four bandpassfilters 302, 304, 306, 308. Likewise, an SP4T switch can replace thethree SPDT switches SW13, SW14, SW16 at the output. As would be apparentto one of skill after reading this description, other switchconfigurations can be used for diplexers having a different number ofbandpass filters. For example, an SPXT switch can be used to select fromamong X bandpass filters in a switchable diplexer, where X representsthe number of bandpass filters.

Multi-throw switches typically exhibit different isolations betweendifferent terminal pairs for a given frequency range. In variousembodiments, the contacts of the multi-throw switch assigned to eachbandpass filter can be selected based on the relative isolations betweenpairs of those contacts.

In yet another embodiment, the switches can be configured to include anadditional position to improve isolation. In operation, for an unusedbranch of the diplexer circuit, the switches can be placed in the unusedposition to increase isolation. Additionally, this unused position canbe grounded to further improve isolation. FIG. 4 is a diagramillustrating an example of this alternative embodiment. Referring now toFIG. 4, in this example, the secondary switches SW12, SW13, SW15 andSW16 include an additional position that is tied to a signal ground.That is secondary switches SW12, SW13, SW15 and SW16 each include atleast one position for each branch and at least one additional positionthat is tied to signal ground. In operation, when one or more branchesof the switchable diplexer are unused, the secondary switches servingthose branches can be switched to the grounded position, therebyimproving the isolation provided.

For example, in the embodiment illustrated in the example of FIG. 4,primary switches SW11 and SW14 are set to select the upper branches ofthe switchable diplexer 302. Isolation from these switches ISO11 andISO14 provides a given level of signal isolation from the two D-bandbranches. Additionally, switches SW15 and SW16 are set to the groundedposition as shown to provide further signal isolation for a portion ofthe signal that might pass through the isolation ISO11 and ISO14provided by primary switches SW11 and SW14. Similarly, if primaryswitches SW11 and SW14 were set to select the D-band branches ofswitchable diplexer 302, then secondary switches SW12 and SW13 could beset to their respective grounded positions to provide isolation fromunwanted signals in those branches.

In further embodiments, conventional multi-band diplexers can becombined with switchable diplexers to provide enhanced functionality. Insuch embodiments, a combination of bandpass filters, diplexers andswitches are provided to support communication and selection of multiplebands. For example, in a video distribution network such as a home oroffice cable TV installation, conventional diplexers can be provided toallow CATV signals to share the coaxial cable runs with MoCA or othernetwork traffic. These diplexers can also be combined with switchingcapability to allow selection of a desired band for network traffic. Instill further embodiments, these diplexers can be combined withadditional filters and switching capabilities to provide further supportfor additional network bands.

FIG. 5 is a diagram illustrating an example implementation of such acombination of bandpass filters, diplexers and switches to addressmultiple bands. The illustrated example supports cable TV signals aswell as the following MoCA bands: Extended-D; D-low; D-high; E, F and H.This example implementation is now described with reference to FIG. 5.After reading this description, it will become apparent to one ofordinary skill in the art how the combination of diplexers and switchesand filters can be implemented using other filters, other diplexers, andother arrangements of components. The example of FIG. 5 includes threebandpass filters 403, 405, and 407, 3 diplexers 410, 411, and 412, andthree switches SW21, SW22, and SW23. E-band bandpass filter 403 as apassband range of 475 675 MHz, F-band bandpass filter 405 has a passbandrange of 650 MHz-875 MHz, and H-band bandpass filter 407 has a passbandrange of 950 MHz-1050 MHz. The cable TV and D-band frequency bands areaccommodated using three diplexers 410, 411 and 412. Diplexers 410, 411,412 are each configured to handle two different frequency bands. D-banddiplexer 410 is configured to pass D-band signals from 1125 MHz-1675MHz, and cable TV signals below 1002 MHz. D-low band diplexer isconfigured to pass signals in the 1125 MHz-1225 MHz passband as well ascable TV signals below 1002 MHz. D-high band diplexer is configured topass signals in the 1350 MHz-1675 MHz passband and cable TV signalsbelow 1002 MHz. In other embodiments, the diplexers can include alow-pass filter configured to have a passband for other TV signals suchas, for example, a passband of less than or equal to 864 MHz.

The combination diplexer 400 can be used to provide communications ofnetwork signals (such as, for example, MoCA signals) in combination withcable TV signals. In the illustrated example, diplexer 400 is connectedto the coaxial cable at common port 422. Common port 422 can be, forexample, an F connector at the wall outlet, or other coaxial cablesourcing cable TV signals and connected to network equipment.Accordingly combination diplexer 400 can receive cable TV signals aswell as network signals through common port 422 and distribute cable TVsignals and network signals at its output on the left-hand side of thepage. Although cable TV signals are generally provided in one direction,networking signals, including the example MoCA network signals, mayinvolve bidirectional communication.

With continued reference to FIG. 5, example operational scenarios arenow described. In this example configuration, switches SW21 and SW23 aresingle-pole-six-throw (SP6T) switches that can be used to select one ofthe available communication bands: E-band, F-band, H-band or theD-bands.

When either of the D-band, D-low band or D-high band are selected inthis example, cable TV signals at or below 1002 MHz are also passedthrough the combination diplexer 400 by the respective diplexer 410,411, or 412. Accordingly, switch SW22, which in this example is a singlepole triple throw (SP3T) switch, is used in conjunction with switchesSW21 and SW23 to select the appropriate diplexer 410, 411, 412 to passthe cable TV signals. In some embodiments switches SW21, SW23 areconfigured through mechanical or electronic coupling to choose the samebandpass filter or diplexer. In further embodiments switch SW22 iscoupled mechanically or electronically to either or both switches SW21,SW23 such that when a D-band diplexer is selected for networkcommunications, the same D-band diplexer is selected by SW22 to allowthe cable TV signals to pass through to the set-top box or other cableTV tuner.

For example, in some embodiments, switches SW21 and SW22 can beimplemented as a ganged switch or as a double pole switch such that whenone of terminals C, D or E of switch SW21 is selected, the correspondingterminal A, B or C of switch SW22 is also selected. In otherembodiments, a processor or other controller can be used to control theswitching through the use of control signals, and the control signalscan be configured to be sent to switches SW21 and SW22 to control theswitch selection in a coordinated manner. Accordingly, when thecontroller causes one of terminals C, D or E of switch SW21 to beselected, it also causes the corresponding terminal A, B or C of switchSW22 to be selected. This can be accomplished by routing the samecontrol signals to both switches, or by configuring (e.g., programming)the controller to send the appropriate control signals to both switchesto achieve this coordination.

In yet another embodiment, the D-band diplexers of the example in FIG. 5are replaced by D-band bandpass filters and the cable TV signals arerouted separately. FIG. 6 is a diagram illustrating an example of aswitchable diplexer with a separate communication path for cable TVsignals. Referring now to FIG. 6, in this example, the switchablediplexer 500 includes six bandpass filters for communication of 6network bands, which in this example are MoCA bands. These bandpassfilters are E-band bandpass filter 403, F-band bandpass filter 405,H-band bandpass filter 407, D-band bandpass filter 414; D-low bandbandpass filter 415 and D-high band bandpass filter 416. Switch SW25,low pass filter 418 and signal path 422 are provided to allow selectionof cable TV signals. In this embodiment as compared to that of FIG. 5,D-band diplexers are not used, and instead, D-band bandpass filters areprovided to allow selection of D-band network communications and cableTV low pass filter is used to allow communication of cable TV signals toa set top box or other cable TV tuner. As a result, switch SW23 is notneeded and a SPST switch SW24 can be used in its place. Switch SW24 canbe mechanically or electronically coupled to switches SW21, SW23 toallow common control of the switching.

FIG. 7 is a diagram illustrating an example of a cascaded switchablediplexer in accordance with one embodiment of the systems and methodsdescribed herein. Referring now to FIG. 7, switchable diplexer 600includes bandpass filters and a diplexer for communication of 4 networkbands, which in this example are MoCA bands. The bandpass filters areE-band bandpass filter 603 and F-band bandpass filter 604 forcommunicating network communications in the E and F bands. The diplexerin the illustrated example is an extended D-band diplexer 602 that isconfigured to pass signals in the 1125 MHz-1675 MHz range (D-band)through one leg and cable TV signals below 1002 MHz through the otherleg.

Switches SW31 and SW32 are used to select which of the bands are passedby switchable diplexer 600. For example, in the illustrated embodimentswitches SW31 and SW32 can select from among E band, F band and D band.

A D-low band low pass filter 605 is included in this example andconnected in series with D-band diplexer 602, creating a cascaded,switchable diplexer enabling selection of a sub-band from within thepassband of D-band diplexer 602.

Switches SW34 and SW35 are provided to switch a D-low band low passfilter 605 in or out of the circuit. When switches SW31 and SW32 areconfigured to route communications through D-band diplexer 602, switchesSW34 and SW35 can be configured to either pass the signals through D-lowband low pass filter 605 or through shunt 511. When switches SW34 andSW35 are configured to route signals through D-low band filter 605, thecascaded combination of D-low band low pass filter 605 and extendedD-band diplexer 602 operate to create a D-low band bandpass filter witha passband of 1125 MHz-1225 MHz. When switches SW34 and SFW 35 areconfigured to pass the signal through shunt 511, switchable diplexer 600passes signals in both the D-low and D-high bands.

For example, when switches SW34 and SW35 are configured to switch D-lowband low pass filter 605 into the circuit, D-low band low pass filter605 effectively stops signals above 1225 MHz. As a result, the passbandof this cascaded combination is 1125 MHz to 1225 MHz.

Accordingly, the cascaded diplexer includes a diplexer (602 in thisexample) having a plurality of bandpass filters each having a passband;and a second bandpass filter (605 in this example) coupled in serieswith a bandpass filter in the diplexer. Preferably, the second bandpassfilter has a passband that further limits the passband of the diplexer.That is the passband of the series bandpass filter is either a subsetof, or overlaps with, the passband of the bandpass filter in thediplexer. In such embodiments, when the series bandpass filter isswitched into the circuit, it further limits the passband of thecircuit.

FIG. 8 is a diagram illustrating another example of a cascadedswitchable diplexer in accordance with one embodiment of the systems andmethods described herein. In this example, D-high band high pass filter704 with a cutoff frequency of 1350 MHz is added in parallel to D-lowband low pass filter 605. When selected in conjunction with D-banddiplexer 602, this D-high band high pass filter 704 would operate withextended D-band diplexer 602 as a D-high band diplexer.

Although not illustrated in the examples of FIG. 7 or 8, an H-bandbandpass filter could also be included with the switchable diplexer toallow communication of H-band signals. In such embodiments, switchesSW31 and SW32 can be modified to single-pole-four-throw switches toaccommodate the added leg for the H-band bandpass filter. Likewise,other bandpass filters could be added to these or other embodimentsdescribed herein.

Although the example embodiments of FIGS. 7 and 8 are shown as havingone cascaded diplexer circuit leg, it will become apparent to one ofordinary skill in the art after reading this disclosure that additionalcascaded diplexer circuit legs can be included in the design. Likewise,the quantity of parallel bandpass filters (e.g., 403, 405) can bedecreased or increased as needed to accommodate the desired frequencybands. In embodiments where parallel bandpass filters are eliminated,switches SW31, SW32 may also be eliminated.

The example switchable diplexers disclosed herein utilize bandpassfilters with passbands suitable for communication in MoCA bands. It willbecome apparent to one of ordinary skill in the art after reading thisdescription that the systems and methods described herein can beimplemented using bandpass filters and diplexers configured toaccommodate different passbands for communications in differentfrequency bands or for communications with different networkingstandards. It will also be appreciated by one of ordinary skill in theart that the examples described herein can be modified with fewer or agreater number of bandpass filters or diplexers to accommodate more orless different frequency bands.

The embodiments described herein with respect to FIGS. 5-8 can be laidout and physically configured in accordance with the embodimentsdescribed with reference to FIGS. 3 and 4. That is, the filters in thecombination diplexers and cascaded diplexers can be arranged such thatfilters with like passbands or stop bands can be arranged adjacent toone another, and filters can be kept physically separate where onefilter's stop band overlaps with (partially or completely) anotherfilter's passband. Additionally, where one filter's stop band overlapswith (partially or completely) another filter's passband, those filterscan be placed on separate secondary switches (e.g., as is the case withF-band bandpass filter 304 and D-low band bandpass filter 306 in FIG. 3)to better isolate those filters.

Although the systems and methods set forth herein are described in termsof various exemplary embodiments and implementations, it should beunderstood that the various features, aspects and functionalitydescribed in one or more of the individual embodiments are not limitedin their applicability to the particular embodiment with which they aredescribed, but instead can be applied, alone or in various combinations,to one or more of the other embodiments, whether or not such embodimentsare described and whether or not such features are presented as being apart of a described embodiment. Thus, the breadth and scope of thepresent invention should not be limited by any of the above-describedexemplary embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time. Likewise, where this document refers totechnologies that would be apparent or known to one of ordinary skill inthe art, such technologies encompass those apparent or known to theskilled artisan now or at any time in the future.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent.

Additionally, the various embodiments set forth herein are described interms of exemplary block diagrams, flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

1. A switchable filter and diplexer circuit, comprising: (a) a pluralityof diplexers, each diplexer having a plurality of passbands; (b) aplurality of bandpass filters, the bandpass filters having apredetermined passband, wherein at least some of the bandpass filtershave a passband different from the passband of the other of theplurality of bandpass filters; and (c) a plurality of switches coupledto the diplexers and to the passband filters and configured to selectone of the plurality of bandpass filters or diplexers for signalcommunication on a communication channel.
 2. The switchable filter anddiplexer circuit of claim 1, wherein the bandpass filters are arrangedin groups of bandpass filters located adjacent to one anotherphysically, wherein a group of bandpass filters comprises a plurality ofbandpass filters having a stop band in a common frequency range ofinterest.
 3. The switchable filter and diplexer circuit of claim 1,wherein the plurality of switches comprise a first pair of switchescoupled to the plurality of bandpass filters and diplexers andconfigured to select one of the bandpass filters and diplexers fornetwork communication, and a third switch having input terminals coupledto the diplexers and configured to select one of the diplexers for TVsignal communication.
 4. The switchable filter and diplexer circuit ofclaim 3, wherein the third switch is coupled to at least one of theswitches of the first pair of switches such that when a given diplexeris selected by the at least one of the switches of the first pair ofswitches that same diplexer is selected by the third switch.
 5. Theswitchable filter and diplexer circuit of claim 1, wherein the bandpassfilters comprise an E-band bandpass filter, an F-band bandpass filterand an H-band bandpass filter electrically arranged in parallel relationto one another and the diplexers comprises a first diplexer with aD-band bandpass filter, a second diplexer with a D-low band bandpassfilter, and a third diplexer with a D-high band bandpass filterelectrically arranged in parallel relation to one another.
 6. Theswitchable filter and diplexer circuit of claim 5, wherein the diplexersfurther comprise a cable TV bandpass filter.
 7. The switchable filterand diplexer circuit of claim 6, wherein the cable TV bandpass filtercomprises a low-pass filter configured to have a passband of less thanor equal to 1002 MHz or a passband of less than or equal to 864 MHz. 8.The switchable diplexer of claim 1, wherein the plurality of bandpassfilters having a stop band in a common frequency range of interestcomprises a plurality of bandpass filters each having an identifiedrejection frequency range that is at least partially overlapping anidentified frequency rejection range of the other bandpass filters inthe group.
 9. The switchable diplexer of claim 6 8, wherein theidentified rejection frequency range is a predetermined frequency rangeof high rejection.
 10. A switchable filter and diplexer circuit,comprising: (a) a first switch comprising a common terminal and aplurality of selectable terminals; (b) a second switch comprising acommon terminal and a plurality of selectable terminals; (c) a thirdswitch comprising a common terminal and a plurality of selectableterminals; (d) a plurality of diplexers, each diplexer having aplurality of passbands and each diplexer having a first terminalconnected to one of the plurality of selectable terminals of the firstswitch, a second terminal connected to one of the plurality ofselectable terminals of the third switch, and a third terminal connectedto one of the plurality of selectable terminals of the second switch;and (e) a plurality of bandpass filters, the bandpass filters having apredetermined passband, wherein at least some of the bandpass filtershave a passband different from the passband of the other of theplurality of bandpass filters, each of the bandpass filters having afirst terminal connected to one of the plurality of selectable terminalsof the first switch, a second terminal connected to one of the pluralityof selectable terminals of the third switch.
 11. The switchable filterand diplexer circuit of claim 10, wherein the bandpass filters comprisean E-band bandpass filter, an F-band bandpass filter and an H-bandbandpass filter electrically arranged in parallel relation to oneanother and the diplexers comprises a first diplexer with a D-bandbandpass filter, a second diplexer with a D-low band bandpass filter,and a third diplexer with a D-high band bandpass filter electricallyarranged in parallel relation to one another.
 12. The switchable filterand diplexer circuit of claim 11, wherein the diplexers further comprisea cable TV bandpass filter.
 13. The switchable filter and diplexercircuit of claim 12, wherein the cable TV bandpass filter comprises alow-pass filter configured to have a passband of less than or equal to1002 MHz or a passband of less than or equal to 864 MHz.
 14. Theswitchable filter and diplexer circuit of claim 10, wherein the bandpassfilters are arranged in groups of bandpass filters located adjacent toone another physically, wherein a group of bandpass filters comprises aplurality of bandpass filters having a stop band in a common frequencyrange of interest.
 15. The switchable diplexer of claim 11, wherein theplurality of bandpass filters having a stop band in a common frequencyrange of interest comprises a plurality of bandpass filters each havingan identified rejection frequency range that is at least partiallyoverlapping an identified frequency rejection range of the otherbandpass filters in the group.
 16. The switchable diplexer of claim 15,wherein the identified rejection frequency range is a predeterminedfrequency range of high rejection.
 17. The switchable filter anddiplexer circuit of claim 10, wherein the bandpass filters and diplexersare grouped into M groups of N bandpass filters or diplexers each,wherein the first and third switches comprise a first and third switchpair for each group of bandpass filters or diplexers, and furthercomprising a first primary switch having a common terminal and at leastM selectable terminals, and a second primary switch having a commonterminal at least M selectable terminals, wherein corresponding ones ofthe selectable terminals of the first and second primary switches areconnected to the common terminals of the first and third switches for agiven group of bandpass filters or diplexers.
 18. The switchable filterand diplexer circuit of claim 17, wherein N is the same quantity ofbandpass filters or diplexers for each of the M groups.
 19. Theswitchable filter and diplexer circuit of claim 17, wherein N is adifferent quantity of bandpass filters or diplexers for one or more ofthe M groups.
 20. The switchable filter and diplexer circuit of claim10, wherein the second switch is coupled to at least one of the firstand second switches such that when a given diplexer is selected by theat least one of the first and second switches that same diplexer isselected by the second switch.